LOS ANGELES (CNN) -- Comedic actor Phil Hartman and his wife, Brynn, were found shot to death Thursday in their Los Angeles home in what police say appears to be a murder-suicide initiated by Mrs. Hartman.

At about 6:20 a.m., police responded to a 911 call that shots had been fired at the family's home in the suburban Encino section of Los Angeles, a house Hartman had dubbed "The Ponderosa."

When they arrived, police found a 9-year-old boy and a
6-year-old girl, believed to be the Hartmans' children, unharmed in the house. As they were moving the second child out of the residence, officers heard a single shot.

They then went to a bedroom in the house where the shot originated and found the bodies of the couple, who had married in 1987.

"We know for sure (Brynn Hartman) inflicted her own gunshot wound, and she apparently shot herself as the officers were in the house," said Lt. Anthony Alba of the Los Angeles Police Department. "Mr. Hartman had been dead for a while. He did not die at the same time that Mrs. Hartman apparently killed herself."

Police not able to confirm motive

An officer removes a child from the house

While neighbors had told reporters that the couple had been having marital problems, LAPD Cmdr. David Kalish said police have yet to confirm that information. A neighbor who declined to give her name told CNN, "It's been building, but I didn't think it would lead to this."

A friend of Phil Hartman's, actor Steve Guttenberg, told CNN he saw no signs of martial trouble, describing the Hartmans as "a very happy couple, and they always had the appearance of being well-balanced."

Susan Kaplow, a neighbor in the upscale San Fernando Valley neighborhood, said Mrs. Hartman appeared happy on Wednesday.

"She left me a really happy message yesterday," Kaplow said. "Everything was fine. We leave each other silly messages all the time."

Phil Hartman, 49, was born in Canada and grew up in Connecticut and Southern California. He got his break in the Los Angeles comedy troupe called "The Groundlings." He was perhaps best known for the eight seasons he spent on "Saturday Night Live," where he impressed audiences with his impressions of more than 70 famous people, including President Clinton, talk show host Phil Donahue and televangelist Jimmy Swaggart.

Most recently, he had starred in the NBC sitcom "NewsRadio," where he played vain, self-centered radio host Bill McNeal. The show had been renewed for another season. Hartman also did some of the voices in "The Simpsons" on Fox.

NBC West Coast President Don Ohlmeyer said Hartman "was blessed with a tremendous gift for creating characters that made people laugh. But more importantly, everyone who had the pleasure of working with Phil knows that he was a man of tremendous warmth, a true professional and a loyal friend."